The article "A marker for the end of adolescence" by Roenneberg et al. (2004) introduces a new method to identify the end of adolescence based on sleep patterns. The study defines mid-sleep time on free days (MSF) as the midpoint between sleep onset and awakening times on days without work or social obligations. This measure helps to account for sleep debt accumulated during the work week, which varies systematically with chronotype. The authors propose a corrected mid-sleep time (MSFsc) to remove the influence of sleep debt. They also introduce the Munich ChronoType Questionnaire (MCTQ) as an alternative to the Morning-Eveningness questionnaire (MEQ), which is validated through various methods, including correlations with circadian parameters like melatonin and cortisol rhythms. The study concludes that average sleep duration and chronotype are controlled independently, and the MCTQ shows good agreement with MEQ scores.The article "A marker for the end of adolescence" by Roenneberg et al. (2004) introduces a new method to identify the end of adolescence based on sleep patterns. The study defines mid-sleep time on free days (MSF) as the midpoint between sleep onset and awakening times on days without work or social obligations. This measure helps to account for sleep debt accumulated during the work week, which varies systematically with chronotype. The authors propose a corrected mid-sleep time (MSFsc) to remove the influence of sleep debt. They also introduce the Munich ChronoType Questionnaire (MCTQ) as an alternative to the Morning-Eveningness questionnaire (MEQ), which is validated through various methods, including correlations with circadian parameters like melatonin and cortisol rhythms. The study concludes that average sleep duration and chronotype are controlled independently, and the MCTQ shows good agreement with MEQ scores.